Maintaining teeth in their corrected positions after treatment is often the most challenging part of an orthodontic treatment plan. Relapse following orthodontic treatment is traditionally thought of as a move back towards the original malocclusion. However, a return towards the initial malocclusion does not always occur, and relapse could be considered as any unfavourable change in tooth position after orthodontic treatment away from a corrected malocclusion. These changes may also be the result of normal age-related effects.Clinicians involved in orthodontic treatment need to have a...